Разберем каждое уравнение и найдем его корни.
- 5 + x2 = (x + 1)(x + 6);
5 + x2 = x2 + 6x + x + 6;
5 + x2 = x2 + 7x + 6;
7x = 5 - 6;
7x = -1;
x = -1/7.
Ответ: x = -1/7
- 2x(x - 8) = (x + 1)(2x - 3);
2x2 - 16x = 2x2 - 3x + 2x - 3;
2x2 - 16x = 2x2 - x - 3;
-16x + x = -3;
-15x = -3;
x = -3 / -15;
x = 1/5.
Ответ: x = 1/5
- (3x - 2)(x + 4) - 3(x + 5)(x - 1) = 0;
3x2 + 12x - 2x - 8 - 3(x2 - x + 5x - 5) = 0;
3x2 + 10x - 8 - 3(x2 + 4x - 5) = 0;
3x2 + 10x - 8 - 3x2 - 12x + 15 = 0;
-2x + 7 = 0;
-2x = -7;
x = 7/2;
x = 3.5.
Ответ: x = 3.5
- x2 + x(6 - 2x) = (x - 1)(2 - x) - 2;
x2 + 6x - 2x2 = 2x - x2 - 2 + x - 2;
-x2 + 6x = -x2 + 3x - 4;
6x - 3x = -4;
3x = -4;
x = -4/3;
x = -1 1/3.
Ответ: x = -1 1/3